Combustion regulator



June 25, 1940. E. F. GOEBEL 2,205,649

COMBUSTION REGULATOR Filed June 1, 1937 2 Sheets-Sheet l Fatented june 25 i946 UNITED" STATES PATENT OFFICE 2,205,649 COMBUSTION REGULATOR Edward F. Goebel, Grand Rapids, Mich. Application June 1, 1937, Serial No. 145,685 8 Claims. (01. 236-29) '10 this specification is used in its broadersense and means a combined boiler and furnace in which combustion occurs and steam is generatedto create-steam pressure. The device is applicable to boilers of either low pressure or high pressure type which produce steam for any purpose either for heater power..

The invention is for the purpose of automatically controlling the combustion in the boiler to maintain a predetermined steam pressure and 29 acts to reduce the combustion and retain the heat when the steam pressure rises above a predetermined point and to increase combustion when the steam pressure falls below a predetermined point. The device also automatically operates to reduce combustionwhen the water level in the boiler falls below a predetermined height.

A further purpose of this invention is to provide means by which the heat produced in the boiler may be. controlled and. maintained at temperatures between minimum and maximum. A

further purpose of the invention. is to provide means for minimizing the steam pressure in the regulator and the exhaust therefrom resulting in reduced cost of construction and operation of the regulator. V

The regulator will function to control and conserve the heat produced by any conventional means such as a hand firedfurnace, an automatic stoker fired furnace or a gas furnace.

The invention provides. various new and useful features of construction and arrangement as hereinafter more fully described and particu larly pointed out in the claims, reference being had to the accompanying drawings in which, Fig. 1 is a side elevation of a portion of a boiler equipped with a coal stoker and having a regulator embodying this invention applied thereto. I

Fig. 2 is a'sectional elevation of the principal part ofthe regulator. I V

Fig. 3 is a bottom View of the regulator. Fig. 4 is a fragmentary elevation illustrating the means for mounting the regulator, and

Fig. 5 is a sectional elevation of the water le e -Wi W inder head 9.

Like numbers refer to like parts in all of the figures.

i represents the boiler having a smoke stack 2, the boiler being a combination furnace and boiler to produce steam. The boiler illustrated '5 is equipped with a conventional stop and start electrically operated coal stoker 3. This type of coal Stoker, when in operation, feeds coal to the furnace and at the same time induces a draft for combustion. It either operates at full '10 capacity or is idle.

The smoke stack {has a damper 4 pivotally mounted in the conventional manner and may be moved to open or closed position by rotation on its pivot and for actuation it is provided on 15 the outside of the stack with a quadrant 5 and a. weight 6- which normally moves the damper to closed position. A steam pipe 1 communicates with the boiler and in which steam exists at the same pressure as that in the boiler. V I

The regulator comprises a cylinder 8 having a lower head 9 and an upper head iii. "A pis- I ton ll within the cylinder is mounted on a piston rod l2 which extends through the lower cyl- A sleeve l3 surrounds the piston 25 rod l2 below the piston .and engages the lower cylinder head 9 to limitthe downward movement of the piston. The. piston heads 9 and in may be connected to the cylinder in any suitable manner, the structure illustrated having recesses in each of the heads to receive the respective ends ,of the cylinder and threaded clamping rods l4 connecting the respective heads and holding them in place upon the cylinder.

The upper cylinder head I!) has a recess and forms a chamber l5 closed at its upper side by a flexible diaphragm it. The diaphragm I6 is held in place by being clamped between the cylinder head ill and the cap I! located above it, machine screws |8 serving as fastening means. A passage 19 leads from the exterior of the cylinder head ID to the chamber l5 therein and a pipe 20 communicates between the passage i9 and the steam pipe I of the boiler transmitting steam from the boiler to the chamber IS. A; waste pipe Zila provided with a shut-01f valve 20b may be connected withthe pipe 20 for clean out purposes and to dispose of condensation in the pipe.

A valve seat 2| having a passage therethrough is fixedin an opening through the cylinder head It) and serves as a communication between the chamber l5 and the upper end of the cylinder 8. A valve 22 coacts with the valveseat Zlt'o between the chamber [5 and the cylinder 8. The valve 22 is connected to the diaphragm l6 and a spring 23 located in a cavity in the cap I! tends to move the center portion of the diaphragm l6 downward and the valve 22 to closed position against its seat. An adjusting screw 24 threaded through the upper end of the cap I! engages a disk 25 at the upper end of the spring 23 and adjusts its tension or the force with which it presses the valve 22 against its seat.

A passage 26 through the cylinder head It communicates with the interior of the upper end of the cylinder 8 and a pipe 21 leads from the passage to a point of waste disposal. An escape valve 28, subject to delicate adjustment, is located in the pipe 21. A pressure gauge 29 may be connected into the pipe 21 between the valve 28 and the cylinder 8 to indicate pressure existing within the cylinder.

A lever 30 is pivotally hung by a link 3| connected to an arm 32 extending from the lower cylinder head 9. The link 3i connects with the lever 36 between its ends and preferably closer to one end than the other, the lower end of the piston rod l2 being pivotally connected to the short end of the lever. On the long end of the lever, or that end opposite the link (it to the end connected to the piston rod, a plurality of adjustable connectors 33 are mounted which may be fixed by suitable means, such as set screws, at desired positions lengthwise of the lever. From one of the connectors 33 a weight 34 is hung which tends normally to move the outer or long end of the lever 30 downwardly and the piston i i upwardly. To another of the connectors 33 a cable 35 is attached which extends, over suitable guides such as the pulley 36, to the quadrant 5 to which it is connected and when pulled the cable 35 serves to move the stack damper 4 to open position, lifting the weight 6 in doing so.

A valve 31 is located in the steam supply pipe 20 adjacent the cylinder head Hi and controls the rate or flow of steam into the chamber it. This valve is of the type which is opened and closed by rotation of a valve stem and is actuated its entire range of opening or closing position by a fraction of one rotation thereof. A lever 38 is provided to actuate the valve and is rotatably mounted on the valve stem til on one of its ends. A disk 46 is attached to the valve stem and has an arcuate slot M. A clamping screw 42 with nut projects through the lever 38 and the slot 4i and provides means for connecting the lever 38 to the valve stem 39 and for rotatable adjustment of such connection.

An arm 43 is fastened to the piston rod l2. A post M extends through the outer end of the arm and is provided with nuts it; by which it may be longitudinally adjusted and a connecting rod 28 is pivotally connected to the post. The upper end of the connecting rod 46 is adjustably and pivotally connected to the lever 38 by means of a pivot pin 47 which passes through the connecting rod and through any of the plurality of holes ll! spaced longitudinally of the lever 38.

The regulator may be located at any suitable point but in most cases it is preferable to locate it near the boiler and many times it is connected to the side of the boiler. For convenience and solidity a bracket 49 projects from the upper cylinder head ill for the purpose of mounting the regulator. This bracket 49 may be attached to any suitable fixed object as a bracket 51] attached to the side of the boiler I.

For the purpose of actuating the regulator relative to the water level in the boiler a float chamber 55. is provided extending both above and below the normal water level of the boiler. The lower part of the float chamber communicates with the boiler below the water level by a pipe 56 and the upper end of the chamber communicates with the boiler above the water level by pipe 51. A steam pipe 58 communicates with the upper end of the chamber 55 and with the interior of the cylinder 8 by joining to the pipe 21 between valve 28 and the cylinder. A float valve 59 actuated by a float B0 normally closes the communication between the float chamber 55 and the steam pipe 58 but when the water level drops below the predetermined or normal height the float 60 will lower and permit the valve 59 to open such communication.

The start and stop stoker illustrated is actuated by an electric motor, the current to the motor being controlled by an electric switch 10- cated in a box 65 attached to the side of the cylinder 8 for convenience. This switch has an operating rod 66 extending downwardly and attached to an arm 61 mounted upon and movable with the piston rod ii. The switch is opened and closed by movement of the rod 66 through a fractional part of the movement of the piston rod i2 in its upper position, movement of the rod upwardly closing the switch and downward movement of the rod opening the switch. Although the rod 6t moves through the whole range of movement of the piston rod I2 the switch is operated only during the fractional upper movement of the rod. The electric switch within the box 65, the electric motor to operate the stoker and the wiring diagram are not shown inasmuch as they are all conventional and well known to those skilled in the art.

Operation As previously explained the regulator may be used to control the heat produced by substantially any heat source but in each case its operation is substantially similar, that is, steam pressure in the boiler, when sufficiently high to enter the cylinder 8 past the valve 22, or when entering the cylinder 8 through the pipe 58 by reason of abnormal low water level, moves the piston I I downwardly. This downward movement of the piston H, through different instrumentalities in different cases, reduces or stops the combustion in the furnace and at the same time closes the stack damper 4 so that the heat which has been developed is conserved within the boiler. Reduction of pressure within the cylinder 8, caused either by reduction of pressure in the boiler or stoppage of communication through the pipe 58 by reason of increased water level in the boiler, permits the piston H to rise which opens the stack damper 4 and increases or starts combustion in the furnace. v

Describing the equipment illustrated, the valve 31 in the steam supply pipe 20 is adjusted when the steam pressure os at the desired maximum and the piston II is at the bottom of its stroke so that the valve 31 is completely or approximately closed. This adjustment is made by loosening the clamping screw 42 so that the disk will be rotated with the lever 38. Upward movement of the piston opens the valve 37, through the connections heretofore described, the extent to which the valve is open being governed by the point of connection with the upper end of the rod 46 to the lever 38.

The escape valve 28 is adjusted to the desired opening, this opening being governed by the conditions under which the equipment operates and relative to the pressure desired to be maintained in the boiler and the rapidity with which it is desired to have the regulator operated.

The regulator is to maintain the steam pressure within a certain range between a maximum and minimum and the spring 23 which closes the valve 22 is regulated so that its tension will permit the valve 22 to open when the pressure in the chamber l5 reaches a point substantially midway between the desired minimum and maximum, this pressure exerting its force against the diaphragm I6 to lift the valve 22 from its seat.

Now assuming that the steam pressure in the boiler has been reduced to the desired minimum the valve 22 is closed and the piston l I has moved to the top of its stroke by action of the weight 34 on the lever 38 and by escape of steam from the cylinder 8 through the valve 28. In this position the stack damper 4 is open and the switch rod 66 has been pushed upward by thearm 61 to close the electric circuit which operates the coal stoker 3 and the stoker operates to produce combustion in the furnace which will raise the pressure in the boiler.

As the steam pressure in the boiler raises this steam under boiler pressure will be conducted through the pipe 28 and the valve 31, which is in relatively open position, to the chamber [5 and when the pressure is sufficiently great to lift the valve 22 against action of the spring 23 the steam will enter the cylinder 8. When the pressure is sufficiently great to raise the valve 22 to the extent that steam will enter the cylinder 8 faster than it will escape through the escape valve 28 pressure will accumulate in the cylinder 8 above the piston II and move the piston down- Ward.

Duringthe first part of the downward movement of the piston the switch rod 65 moves the switch in the box 65 to open position and stops the stoker operation. Before this has happened sufficient latent heat has developed in the furnace so that it will be given off after cessation of the stoker operation and continue to heat the boiler and increase the pressure. As the pressure continues and increases the piston II will be moved farther downward closing the stack damper 4 to a greater extent and preventing the escape of heat through the stack 2 so that the heat will be conserved and the water in the boiler heated by it.

As the piston II moves downward it moves the valve 31 in the steam supply pipe 20 in a closing direction, this valve being more or less closed depending upon the extent of pressure in the pipe 20. As the valve 31 closes it will eventually reach a position where it will not permit the passage of steam faster than it will escape through the escape valve 28 whereat an equilibriumwill be reached and the piston will remain in the position at which the valve 31 has been moved to create the foregoing condition which under the ideal condition is at less than the maximum desired pressure. The position of the piston at which an equilibrium of pressure exists in the cylinder 8 varies under different conditions. If the steam pressure builds up very rapidly in the boiler this high pressure will cause a greater volume of steam to pass the valve 31 at a given opening of the valve than if the pressure were lower and therefore when the pressure has built up rapidly to a relatively high point the piston must move downwardly farther to close the valve 31 to a greater extent before the passage of steamthrough the valve 31 will be reduced in volume to the passage of steam from the escape valve 28 but at some point within the movement of the piston II the valve 31 will be closed sufficiently, because of its original adjustment, so that the steam will not be permitted to enter the cylinder 8 faster than it escapes through the valve 28.

When the steam pressure in the boiler reduces, either by diminution of heatin the furnace or by drawing off of steam from the boiler, to a pres-' sure insuflicient to hold the valve 22 open this valve will close and steam in the cylinder 8 will gradually escape through the valve 28 permitting the piston II to rise by action of theweight 34 and this rising movement will continue until the piston reaches the upper limit of its stroke and when nearing the end of its upward movementthe switch rod 66 closes the electric switch and starts operation of the stoker. From this point the -aforedescribed operation is repeated.

If the water level in the boiler drops below the predetermined point it is imperative to diminish or stop combustion in the furnace regardless of the extent of the pressure in the boiler for the reasons well known to those skilled in the art. Lowering of the water level in the boiler results in likewise lowering of the water level in the float chamber 55 and when this level falls below a predetermined point the float 68 will drop sufficiently to. permit the float valve 59 to open. When this float valve 59 opens the steam under pressure from the boiler flows through the pipe 5! into the upper end of the float chamber 55 and out through the pipe 58 into the pipe 21 and directly without restriction into the cylinmunication with the pine 58 by the floatvalve 59. While the piston I I has been held in its lowermost position the combustion has ben stopped by the instrumentalities heretofore described.

When this regulator is applied to boilers using continuous but variable combustion its connections and operation. although generally the same as heretofore described for the stop and start stoker, they are somewhat different in detail. When. connected with a variable speed stoker the lever 30 is connected by suitable means to actuate the speed controlling device of the stoker so that the stoker will operate to increase the combustion as the piston H rises and to decrease it as the piston lowers normally controlling the stoker to operate continuously but at variable speeds.

When the regulator is connected to a hand fired furnace, the combustion in which is entirely controlled by opening or closing the under draft and the stack damper, the lever 30 is connected by suitable means to open and close the under draft as well as to open and close the stack damper 4 as herein illustrated. When so connected the under draft damper will be caused to open to increase combustion as the piston l l rises and to close to decrease combustion as the piston lowers.

The opening and closing movements of the under 75 draft damper are the same as those of the stack damper 4.

When connected for use as described in the foregoing examples steam. under pressure from the boiler will enter the cylinder 8 and move the piston ll downward, as heretofore described, until an equilibrium in the cylinder 8 has been reached. However, with this type of combustionthe heat in the boiler continues but at less than a maximum degree. Movement of the piston to the position of equilibrium has either reduced the speed of the stoker or has partially closed the dainpersof the hand fired furnace.

With this type of combustion the piston ll seldom moves to either of its extreme positions but will either remain stationary in mid-position, as when a state of equilibrium in the cylinder maintains, or will move downward from that position to further decrease combustion if the pressure in tl 1e boiler rises or will move upward from that position to increase combustion if the pressure in. the boiler lowers.

Of course, under abnormal conditions the boiler pressure may become abnormally high in which case the piston ll willmove to, or nearly to, the limit of its downward stroke to decrease combustion to the minimum. or the boiler pressure may become abnormally low and insufilcient to hold the valve 22 open in which case the piston will move upward to the limit of its stroke increasing combustion to the maximum. But by the various adjustments provided and heretofore explained the regulator may be caused, when operating with a continuous combustion Qurnace, to control the combustion to keep steam pressure nearly constant and between the desired minimum and maximum.

One object attained by this mechanism is that the pressure in the cylinder 8 never rises appre- :iably above that which is needed to move the piston H and the load to which it is connected. This is accomplished by the automatic closing movement of the inlet valve 3'! as the piston moves downward The greatest pressure which an exist in the cylinder 8 is that which will move the piston downward to the limit of its stroke because at thatv lower limit the valve 3! has been closed, because of original adjustment, so that steam will not enter the cylinder ll faster than it escapes through the valve 28.

Therefore, regardless of whatever high pre.. sures may exist in the boiler and pipes leading to the valve 31, only such pressure will be attained in the cylinder 8 as will move the rela .Lvely light load connected to the piston ll. This makes it possible to construct the device of relatively light parts and cheapens its cost considerably.

When the regulator is used with a start and .';top stoker it is not desired that the piston be maintained in mid-position since the stoker operates at full capacity in all positions of the piston excepting at the extreme upper limit of the stroke. Therefore, aiter pressure has been attained sufficient to move the piston downwardly to stop operation of the stoker it is desired to have it continue to the limit of its downward movement in order to completely close the stack damper 4 but it is also desired to have the valve 3 sufilciently closed at the limit of the stroke so that excess pressure will not exist in the cylinder 8. This function is attained by adjustment of the connection of the upper end of the rod 16 to a point near the outer end of the lever 33.

When used with continuous types of combuz tion devices the upper end of the rod 46 is connected to the lever 38 closer to the valve 31 so that agreater valve movement will be attained relative to the movement of the piston H which results in balancing the piston in mid-stroke.

A modification of this structure is conceived which attains substantially the same result but at the expense of a considerable waste of steam. In this modification the valves 31 and 28 are transposed so that there is a constant supply of steam. to the chamber 55. The variable valve now in the exhaust passage is connected to and actuated by the piston rod 82 by substantially the same means as is herein illustrated for operating the valve 3'! excepting that the valve is moved to open and closed positions oppositely to that of the valve 3'! relative to movement of the piston II. In other words the exhaust valve of the modification opens with downward movement of the piston II and vice versa.

The operation of this modified structure re sults in increasing the exhaust volume as the piston moves downward and balancing the pressure on the piston in this manner. The modified structure has been used with considerable success but because of the excessive waste of steam, especially when the piston is in lower position, it considered inferior to the preferred form herein shown.

I claim:

1. The combination with a combination boiler and furnace, of a regulator therefor comprising, a cylinder and a piston, means actuated by movement of said piston to control combustion in the furnace, a steam conduit communicating between the boiler and the cylinder at one side of said piston, a normally closed pressure actuated valve in said steam conduit, a constantly open exhaust passage from said cylinder at the same side of the piston as said steam conduit communication, and means actuated by movement of said piston to vary the relation between the volume of steam entering said cylinder through said conduit and the volume of steam passing from said cylinder through said exhaust passage.

The combination with a combination boiler and furnace, of a regulator therefor comprising, a cylinder and a piston, means actuated by movement of said piston to control combustion in the furnace, a steam conduit communicating between the boiler and the cylinder at one side ofsaid piston, a constantly open exhaust passage from said cylinder at the same side of the piston as said steam conduit communication, a

valve in said steam conduit, means for operating said valve by movement of said piston and :1 normally closed pressure opened valve in said steam conduit between said valve and said cylinder.

3. The combination with a combination boiler and furnace, of a regulator therefor comprising, a cylinder and a piston, means actuated by movement of said piston to control combustion in the furnace, a steam conduit communicating between said boiler and said cylinder, a normally closed pressure actuated valve in said steam conduit, a constantly open exhaust passage from said cylinder, a second valve in said steam conduit including a valve stem adapted to be moved to open or close said valve, and means secured to said valve stem and actuated upon movement of saidpiston to open or close said valve.

l. The combination of elements defined in claim 3, said valve stem being rotatable, and said last named means acting to rotate said valve stem to open or close said valve,

5. The combination with a combination boiler and furnace, of a regulator therefor comprising,

a cylinder and piston, means actuated by movement of said piston to control combustion in the furnace, a steam conduit communicating between the boiler and cylinder, a normally closed pressure actuated valve in said steam conduit, an exhaust conduit communicating with said cylinder and a valve located in one of said conduits and actuated by movement of said piston acting 'to vary the ratio between the volume of steam entering said cylinder and the volume of steam passing from said cylinder throughout the entire movement of said piston.

6. The combination with a combination boiler and furnace comprising, a cylinder and a piston, means actuated by movement of said piston to control combustion in said furnace, steam conduit means communicating between the boiler and cylinder, a normally closed pressure actuated valve in said steam conduit, an exhaust passage from said cylinder, a second valve in said steam conduit and means for opening and closing said second valve by movement of said piston acting to move the valve toward closed position when the piston is moved by increased steam pressure.

,7. The combination with a combination boiler and furnace comprising, a cylinder and a piston, means actuated by movement of said piston to control combustion in said furnace, steam conduit means communicating between the boiler and cylinder, a normally closed pressure actuated valve in said steam conduit, an exhaust passage from said cylinder, 2. second valve in said steam conduit, means for opening and closing said second valve by movement of said piston acting to vary the rate of opening and closing said second valve relative to the movement of the piston.

8. The combination with a boiler and furnace comprising, a cylinder and a piston, means actuated by movement of said piston to control combustion in said furnace, steam conduit means communicating between the boiler and cylinder, a normally closed pressure actuated valve in said steam conduit, an exhaust passage from said cylinder, a second valve located between said pressure actuated valve and the boiler and means for opening and closing said second valve actuated by movement of said piston.

EDWARD F. GOEBEL. 

